Contact for electrical apparatus.



T. A. EDI-SON.

CONTACT FOR ELECTRICAL APPARATUS.

APPLICATION FILED JUNE 13. 1912.

PatentedSept. 7, 1915.

THOMAS A. EDISON, OF LLEWELLYN PARK: WEST ORANGE, NEW JERSEY, ASSIG'NOB.TO NEW JERSEY PATENT COMP-ANY, OF WEST ORANGE, NEW JERSEY, A CORPORATIONOF NEW J EBSEY.

CONTACT FOR ELECTRICAL APPARATUS.

Specification of Letters Patent.

Patented Sept. '7, 1915.

Application filed June 13, 1912. Serial No. 703,368:

To all whom it may concern Be it known that I, THOMAS A. EDISON, acitizen of the United States, and a resident of Llewellyn Park, WestOrange, Essex county, New Jersey, have inventedcertain new and usefulImprovements in Contacts for Electrical Apparatus, of which the fol- 30,1911, I have disclosed and claimed alternating current rectifierssimilar to that described herein, in which carbon contacts are employedon the vibrating armatures. Said carbon contacts cooperate with blockcon-- tacts of metal and greatly reduce the tendency to spark. l

My present invention has for its object the provision of a simple andefficient form of contact adapted to radiate and dissipate the heatgenerated by the contacts in an eiii cient manner, thereby preventingexcessive rise of temperature, and still further reduc' ing the tendencyto spark.

My invention is described more fully here inafter and claimed. For thefurther description of my invention reference is had to the drawingswhich accompany and form a part of this specification and in. whichFigure 1 is a side elevation of a rectifying device provided with oneembodiment of my improved contact; Fig. 2 is a vertical section of Fig.1; Fig. 3 is a plan view of the same; Fig. 4 is a perspective view ofthe contact; and Fig. 5 is.a diagrammatic view showing the rectifierconnected in the rectifying system.

In the drawings, a frame or base is shown at 1, upon which is mounteda'permanent magnet 2 having an almost completely closed magneticcircuit. Armatures 3 and at are pivotally mounted on the frame so as tobe capableof vibration in the gap of the magnet 2. -The armatures 3 and4: are provided With contacts 5 and 6 respectively, preferably made ofcarbon and secured to the armatures in any suitable manner. A coil 7surrounds the armatures 3 and 4 and is supported between the magnet 2and up wardly extending lugs or projections of the frame 1. An L-shapedmember 8 is secured to one of the poles of the magnet 2 and is insulatedtherefrom by insulating material 21. The insulating material 21 rests onthe magnet 2 and the horizontal arm of the L-shaped member 8 rests onthe insulating material and is secured to the magnet by means of a screw10, which is provided with insulation 22 so as to insulate the L-shapedmember 8 from the magnet. The horizontal portion of the L-sbaped member8 is provided with guides 9 between which is received the adjustablestationary contact. The adjustable stationary contact has a U-shapedportion 23 which is provided with outwardly extending portions 11.Plates 12 and 13 of suitable material, such as copper, are secured oneach side of the outwardly extending projections 11 and the plates 12and 13 and the extensions 11 are riveted together. The copper plates 12and 13 extend vertically upward, have considerable mass, and aresub-divided in order to provide considerable area for radiating anddissipating heat. In the form of contact which I have illustrated. theplates 12 and 13 are provided with upwardly extending teeth, making ofeach of the plates a comb-like member. The vertical arm of the L-shapedmember 8 is provided in its lower portion with an adjusting screw 15,which near its inner end has a reduced portion extended through anopening 14 in the U-shaped portion 22 of the contact. By rotating thescrew 15 the contact is adjusted along the guides 9 in order to insureproper cooperation with the carbon contacts 5 and 6. In the form ofcontact illustrated. the lower portion of the cooper plate 13 serves asa contact surface or face for cooperation with the carbon con-' tacts 5and 6. The vertical arm of the i.-

shaped member 8 is also provided with a,

Referring particularly to Fig.

- nating current mains are shown at 30 and sition. Adjusting screw 15 isprovided with a lock nut 20.'The armatures 3 and 4; are in electricalconnection with the frame or base I through their pivots, and additional5 connecting means may be provided by wires 23 and 2e secured to thearmatures 3 and 4 respectively near their pivots. The other ends of thewires may be secured to the base or frame 1. 5, alter- 31. One terminalof the coil 7 is connected to one of the alternating current mains rentmains 31, and the frame 1 is connected by conductor 36 to a storagebattery or other direct current translating device 37 which in turn isconnected through an ad usta-ble rheostat 38 to the other alternatingcurrent main 30.

The mode of operation of the rectifying device is as follows :-Reversalsof current 130 occur in the coil 7 and-an alternating flux is set up inthe armatures 3 and 4, thereby making the upper ends of the armaturesalternately north and south poles. 3 When the u per ends of thearmatures are of north polarity, the south pole of the magnet isstrengthened and the north pole weakened, and when the upper ends f thearmatures are of south polarity, the north pole of the magnet isstrengthened and the south pole 40 weakened; As a result, the armaturesare vibrated in synchronism with the alternating current flowing throughthe coil 7 When the rectifying. circuit is closed, current flows fromthe alternating current main 30 through the adjustable rheostat-38,storage battery 37, conductor 36, to the frame 0 the rectifier, thencethrough the armatures, carbon contacts and stationary contact toconductor 35, and back to the alter- "nating current main 31. Thiscondition of l'lfi'airs continues during one half wave of thealternating current. During the succeeding half wave, the circuit isbroken between the carbon contacts and the stationary contact. In thismanner uni-directional current is supplied to the storage battery orother direct current translating device 37.

v The adjustable condenser 34 in series with the coil 7 is employed toadvance the phase of the current in the coil in order to compensate forthe inertia of the armatures and to cause the circuit to be broken atthe proper times to avoid sparking. The rheostat 38 is employed toregulate the current supplied to the storage battery 37.

By reason of the considerable mass of the copper plates 12 and 13 andtheir comb-like structure, the heat generated in the contacts is rapidlydistributed through a comparatively large mass of very ood conductingmetal and is rapidly radiated and dissipated. The temperature of thestationary contact is thus prevented from becoming excessiveand thetendency to sparking is materially reduced. As pointed out in my 76prior application: mentioned hereinbefore, the carbon contacts alsocontributeyei'y materially to this result.

Having now described my invention, what I claim as new therein anddesire to protect 80 by Letters Patent is as follows 1. In electricalapparatus, a supportin member, a contact adjustably. mounted thereon,said contact having a portion cooperating with said supporting memberand an upwardly extending recessed portion for radiating and dissipatingheat and means for clamping said contact in adjusted position upon sa1dsupporting member, substantiallyjas described.

2. In electrical apparatus, a metallic contact member comprising asubstantially U- V shaped portion provided with outwardly extendingprojections at the ends thereof, and

lates secured to said projections, said plates .aving subdividedportions for radiating and dissipating heat, substantially as described.L

3. In electrical apparatus, a supporting member having guiding means, ametallic contact member having a portion coiiperating with said guidingmeans, and a plate secured to said portion, said plate having a contactsurface and having also portions subdivided for the radiation anddissipation 10b of heat,-substantially as described.

4. In electrical apparatus, a stationary contact member and a vibratingcontact member adapted to coeperate therewith, the stationary contactmember being provided with a'heat-radiating and dissipating comblikeextension of substantially greater area than the area of contact surfacebetween said contact members, substantially as described.

This specification signed and witnessed this 10th day of J une, 1912.

THOS. A. EDISON.

Witnesses:

HENRY LANAHAN, ANNA R. KLEHM.

